Technology

"Absolute mathematical accuracy exists only in the mind of man. All
practical applications are mere approximations, more or less successful.
And when all has been done that science and art can unite in practice, the
supposition of some defects in the instruments will always be prudent. It
becomes therefore the duty of an observer to combine and invent, upon theoretical
principals, methods of systematical observations, by which the influence
of any error of his instruments may be neutralised, either by direct means,
or more generally by compensation.” In the Principal Documents (1825)
by Ferdinand Hassler, Founder of the United States Survey of the Coast,
Published by New Series, Philadelphia. p.390.

1839 - On Dredging the Depths of the Ocean

"Song of the Dredge”, presented by Edward Forbes to the British
Association at its annual meeting in 1839.

"Hurrah for the dredge, with its iron edge,
And its mystical triangle.
And its hided net with meshes set
Odd fishes to entangle!
The ship may move thro’ the waves above,
‘Mid scenes exciting wonder,
But braver sights the dredge delights
As it roves the waters under.

Chorus:
Then a-dredging we will go wise boys
A-dredging we will go!
A-dredging we will go, a-dredging we will go,
A-dredging we will go, wise boys,
A-dredging we will go!

Down in the deep, where the merman sleep,
Our gallant dredge is sinking;
Each finny shape in a precious scrape
Will find itself in a twinkling!
They may twirl and twist, and writhe as they wist
And break themselves into sections,
But up they all, at the dredge’s call,
Must come to fill collections.

Chorus:

The creatures strange the sea that range,
Though mighty in their stations,
To the dredge must yield the briny field
Of their loves and depredations.
The crab so bold, like a knight of old,
In scaly armour plated,
And the slimy snail, with a shell on his tail,
And the star-fish ----- radiated!

As powerful as the method of “least squares” is, under certain
conditions its most probable estimation of truth may in fact be quite misleading.
Superintendent Bache’s good friend, Harvard mathematician Benjamin
Peirce, pointed this out in a treatise appended to the Coast Survey report
for 1854 under the unlikely name “Report upon the Determination of
Longitude by Moon Culminations.” Although meant as an argument in
favor of his thesis that longitude determinations by moon culminations of
the Pleiades had the potential to be the most accurate possible, this document
is memorable for its lucid discussion of the various types of observational
errors as well as for its understanding of the ultimate attainable limits
of accuracy. As such, Peirce’s major points are applicable to most
types of scientific observation and the paper could be considered a landmark
in American scientific thought.

Peirce began with the supposition that with only one observation of a physical
quantity that observation must be adopted as the true value of the constant.
However, “A second observation gives a second determination, which
is always found to differ from the first. The difference of the observations
is an indication of the accuracy of each, while the mean of the two determinations
is a new determination which may be regarded as more accurate than either. ”

As more and more observations are acquired, "The comparison of the
mean with the individual determinations has shown, in all cases in which
such comparison has been instituted, that the errors of lunar observation
[or most species of scientific observation are subject to law, and are not
distributed in an arbitrary and capricious manner. They are the symmetrical
and concentrated groupings of a skillful marksman aiming at a target, and
not the random scatterings of a blind man, nor even the designed irregularities
of the stars in the firmament. This law of human error is the more remarkable,
and worthy of philosophic examination, that it is precisely that which is
required to render the arithmetical mean of observations the most probable
approach to the exact result. It has been made the foundation of the method
of least squares, and its introduction into astronomy by the illustrious
Gauss is the last great era of this science. ”
Peirce continued: “If the law of error embodied in the method of least
squares were the sole law to which human error is subject, it would happen
that by a sufficient accumulation of observations any imagined degree of
accuracy would be attainable in the determination of a constant; and the
evanescent influence of minute increments of error would have the effect
of exalting man’s power of exact observation to an unlimited extent.
I believe that the careful examination of observations reveals another law
of error, which is involved in the popular statement that ‘man cannot
measure what he cannot see.’ The small errors which are beyond the
limits of human perception, are not distributed according to the mode recognised
by the method of least squares, but either with the uniformity which is
the ordinary characteristic of matters of chance, or more frequently in
some arbitrary form dependent upon individual peculiarities -- such, for
instance, as an habitual inclination to the use of certain numbers. On this
account it is in vain to attempt the comparison of the distribution of errors
with the law of least squares to too great a degree of minuteness; and on
this account there is in every species of observation an ultimate limit
of accuracy beyond which no mass of accumulated observations can ever penetrate.

"A wise observer, when he perceives that he is approaching this limit,
will apply his powers to improving the methods, rather than to increasing
the number of observations. This principle will thus serve to stimulate,
and not to paralyze effort; and its vivifying influence will prevent science
from stagnating into mere mechanical drudgery....” In Annual Report
of the Superintendent of the Coast Survey for 1854 (1855). Appendix 36 “Report
upon the Determination of Longitude by Moon Culminations.” Printed
by A.O.P. Nicholson, Public Printer. pp. 108-120.

1858 - Deep-Sea Sounding Difficulties

"The explorations of the Gulf Stream by officers of our navy, in connection
with the survey of the coast, first gave rise to systematic efforts to determine
sections of the bottom of the sea along lines of great depth; afterwards
the extensive system of deep-sea soundings executed under the direction
of the Navy Department, through the exertions of Lieut. Maury, furnished
most useful experience and results, and more recently the soundings along
the line of the proposed Atlantic telegraph, first by Lieut. Comg. Berryman,
United States navy, and again by Lieut. Comg. Joseph Dayman, R.N., have
shown that to reach the bottom of the sea is not beyond the power of human
effort.

"Notwithstanding so much has been done to overcome the practical difficulties
which formerly embarrassed and discouraged any attempts to sound at great
depths, it is undeniable that much uncertainty exists in the determinations
that have been made even when the depth is not greater than 2,000 fathoms;
while below 2,000 or 2,500 fathoms, the errors and uncertainties amount
to failures; and a limit has been reached beyond which it seems difficult
to pass.

When the subject is viewed as a mechanical problem it seems hardly possible,
however, that insurmountable obstacles can exist to its practical solution.
The facility with which an observer can place himself over any point, the
distance of which below the plane on which he rests it is his object to
determine, and from which he is separated by a medium freely and almost
equally penetrable at all depths, the laws of which are well known, would
seem to offer greater hopes of our being able ultimately, to determine the
depressions of the bottom of the ocean by a greater number of observations,
and with greater accuracy, than the elevations of the continents.

"The solution of the question requires that the difficulties which
have been found to exist in the present methods of sounding, should be clearly
determined and overcome, and when these methods fail, that they should be
improved, if possible, or new ones substituted. . ." In "Investigation
of the laws of motion governing the descent of the weight and line in deep-sea
soundings" (1859) by Prof. W.P. Trowbridge, Assistant in the Coast
Survey. Published in Report of the Superintendent of the Coast Survey Showing
the Progress of the Survey During the Year 1858. Appendix No. 37, published
by William A. Harris, Washington. pp. 228-239.

1858 - Need for Improved Modes of Sounding

"The idea of a ‘plateau’ existing between Newfoundland
and Ireland is not warranted, it seems to me, by any observations that have
yet been made. The range of errors may be as great as 500 fathoms, which
would admit of the existence of a submarine mountain on this line half as
high as Mount Washington. A true section of the Atlantic can only be determined
by improved modes of sounding, since, from the preceding discussion, we
may be warranted in the conclusion that it is practically impossible to
determine the greatest depths of the ocean by the methods now in use.” In "Investigation
of the laws of motion governing the descent of the weight and line in deep-sea
soundings" (1858) by Prof. W.P. Trowbridge, Assistant in the Coast
Survey. Published in Report of the Superintendent of the Coast Survey Showing
the Progress of the Survey During the Year 1858 Appendix No. 37, published
by William A. Harris, Washington. pp. 228-239. Written at the Coast Survey
office, Washington, D.C., May 31, 1858.

1880 - American Pride

"Without specifying the great results obtained from this continuous
research, I may be pardoned in referring with some gratification to the
fact that in the small steamer ‘Blake,’ of only three hundred
and fifty tons burthen, N.M., under the energetic and skillful commands
of Lieutenant-Commander Sigsbee and Commander Bartlett, with a full complement
of forty-five including officers and crew, more rapid work was done than
had been accomplished with the old methods and appliances by the Challenger,
a vessel of over 2,000 tons burthen, with a complement of twenty-nine naval
and civil officers and a correspondingly large crew.” Carlile Patterson
in introduction to “Deep Sea Sounding and Dredging: A Description
and Discussion of the Methods and Appliances Used on Board the Coast and
Geodetic Survey Steamer, Blake,” by Charles D. Sigsbee, 1880. Published
by Government Printing Office, Washington. p. 5.

1880 - Early Advances on the Blake

"A question may naturally arise as to the considerations which would
authorize a notice of the methods and appliances of the Blake’s party.
To this it is replied---

"We were one of the first, after Sir William Thomson, and Capt. George
E. Belknap, U.S.N., to use piano-forte wire for sounding purposes, and we
probably continued its use for a longer time than any other organization.

The Blake is the only vessel that has ever been fitted out with wire rope
(the suggestion of Prof. Alexander Agassiz) for deep-sea dredging and trawling.

But little has been published concerning the use of wire for sounding;
and of wire rope for dredging, nothing, in fact, excepting in a general
account of the Blake's dredging work by Professor Agassiz.

Nearly all the apparatus for sounding and dredging used on board the Blake
is new or modified from previous forms, and is peculiar to that vessel,
the water-cup (Plates 20 and 40) being the first and only instrument in
the field for the performance of the complex work aimed at in its design.

These appliances, which are intended to effect an advance in accuracy or
in celerity of operations, and to secure ultimate economy, have been well
tested in actual service, and are believed to have accomplished, at least
in some degree, the object sought.

Having had unusual facilities, in connection with continuous work, our
methods were perhaps more systematic in certain directions than are generally
followed by parties or organizations for the prosecution of deep-sea work.” In
Deep Sea Sounding and Dredging: A Description and Discussion of the Methods
and Appliances Used on Board the Coast and Geodetic Survey Steamer, Blake
(1880) by C. D. Sigsbee. Published by Government Printing Office, Washington.
p. 12.

1880 - Care in Navigating the Blake

"Our navigation-record was comprehensive, and adapted to future revision
or verification.” In Deep Sea Sounding and Dredging: A Description
and Discussion of the Methods and Appliances Used on Board the Coast and
Geodetic Survey Steamer, Blake (1880) by C. D. Sigsbee. Published by Government
Printing Office, Washington. p. 12.

1880 - Working on the Blake

"The longest continuous run that we ever made on sounding-lines occupied
eleven days, although that length of time was nearly equaled on several
occasions. These long runs were sometimes executed under such trying circumstances
of wind, weather, sea, and current as to impose much mental strain on the
officers and to call forth all the endurance of the crew. At sea, everything
had to give way to the work in hand. If the vessel did not look pretty,
we concluded that we could not help it, and complacently looked forward
to a higher standard on our arrival in port. It was generally understood
and appreciated by all on board that mistakes through carelessness ought
not to be tolerated, and that strictness should rule always in matters immediately
connected with the special purpose of our party. In port, on the contrary,
the fullest liberty of action, not at variance with good order and the interests
of the work, was allowed.” In Deep Sea Sounding and Dredging: A Description
and Discussion of the Methods and Appliances Used on Board the Coast and
Geodetic Survey Steamer, Blake (1880) by C. D. Sigsbee. Published by Government
Printing Office, Washington. p. 12.

A steam winch with steel wire was first used for deepsea dredging on the
Coast Survey Steamer Blake. Source: Deep Sea Sounding and Dredging (1880)
by C. Sigsbee. (Courtesy of NOAA Photo Library.) Click image for larger
view.

1888 - Alexander Agassiz on the First Use of Steel Cable by an Oceanographic
Ship

"My familiarity with the successful use of very long steel ropes for
mining purposes naturally suggested their adaptation to the new purpose
of deep sea work.” In Three Cruises of the Blake (1888) by A. Agassiz.
Published by Houghton, Mifflin, and Company, Boston. p.28.

All dredging cruises previous to the first cruise of the Blake had used
hemp rope for dredging.

1888 - Alexander Agassiz on Ocean Temperatures

"A great objection to the use of Miller-Casella [a maximum - minimum
recording thermometer] for obtaining deep-sea temperatures is found in the
fact that they will register only the lowest temperatures observed.....When,
however, we seek to ascertain the temperatures of the Gulf Stream, or to
work in the Arctic regions, where the coldest water may be nearest the surface,
we are unable, of course, to determine the position of the coldest or warmest
intermediate layers of water. The only perfect method of taking serial temperatures
is one which records them continuously on deck during the descent of the
thermometer. Such an apparatus has been devised by Sir William Siemens.
In the Bakerian Lecture for 1871, he showed that the principle of the variation
with the temperature of the electrical resistance of a conductor might be
applied to the construction of a thermometer, which would be in use in cases
where a mercurial thermometer was not available. The instrument he described
has since been largely used as a pyrometer for determining the temperatures
of hot blasts and smelting furnaces; and it has been found that its indications
agree very closely with those of an air-thermometer. He devised a similar
instrument for measuring temperatures where a much greater degree of accuracy
is required, as in the case of deep sea observations; and during the autumn
of 1881, this deep-sea electric thermometer was subjected to a series of
tests on board the Blake by Commander Bartlett.” In Three Cruises
of the Blake (1888) by A. Agassiz. Volume I. Published by Houghton, Mifflin,
and Company, Boston, pp. 16-17.

1888 - The Working Atmosphere on the Blake

"It is pleasant to notice that the harmony between the naturalists
and officers of the “Blake” was not for an instant disturbed
during the time they were working in common. Everything in the way of naval
routine was sacrificed for the time to the objects of the cruise, and the
appearance of the deck and bow of the Blake was often more that of a mud-scow
than of a vessel in the service of the United States.” In Three Cruises
of the Blake (1888) by A. Agassiz, Volume I, p. 50.

1921 - The Role of Echo Sounding in Exploring the Sea I: A Supplementary
Device

"Depth determinations by means of reflected sound from the bottom
are reported to be feasible; andthough it may never supplant the standard
method of sounding, there is a possibility of it becoming a valuable supplementary
device.” In “Mapping the Pacific - Survey of Shoreline and Coastal
Waters” by Commander J.T. Watkins, U. S. Coast and Geodetic Survey.
Published in The Proceedings of the First Pan-Pacific Scientific Conference,
August 2-20, 1920 (1921). Special Publication Number 7, Part 1, 1921 by
the Bernice P. Bishop Museum.

1926 - The Contribution of Steam Power to Oceanography

"Before steam came in to enable the mariner to keep his ship over
one spot it was quite impossible to take an accurate sounding over 100 fathoms.
The Challenger had moderate steam power, but was not fitted with the excellent
sounding engines and wire line of the present day. She used Italian hemp,
which, as it carried air down in its interstices, went slower and slower
and marked the great depths badly....”

"The weights on the hemp line were so heavy that they were slipped
each time and left at the bottom, and it is possible that in future geological
ages they will be recorded as meteorites that have come from other worlds
or from cosmic space.” In Nature Notes for Ocean Voyagers (1926) by
A. Carpenter and D. W. Barker, 2nd edition. Published by Charles Griffin,
London. p. 4.

1932 - Sailing by the Wind

"Walking aft a few feet we stand at the steering gear of the ship.
There is no cozy; wheel-house on the bridge for the quartermaster of a sailing
ship! He must stand at the very stern, with an unobstructed view of the
sails. When sailing “by the wind” his eye is glued to the weather-side
of the uppermost sail; he keeps it drawing a trace of wind, but never lets
it fill.” In The Last Cruise of the Carnegie (1932) by J. H. Paul.
Published by The Williams and Wilkins Co., Baltimore. p. 36.

1932 - Storms and Too Much Equipment

".... On the next day we had the worst storm of the passage. We were
forced to heave to and ride it out. Several of the bronze fittings in the
rigging were carried away. However, damage was not so serious that emergency
repairs could not be made. The vessel was having a bad time of it. Time
and again seas swept the quarter-deck, something which rarely occurred on
previous cruises. This was probably due to the load carried aft. The new
winch, generators, batteries, and so on, used for our oceanographic work,
weighed several tons.” In The Last Cruise of the Carnegie (1932) by
J. H. Paul. Published by The Williams and Wilkins Co., Baltimore. p. 77-78.

1932 - Hypothesis vs. Reality

"There was one great surprise in the results. All of those who discussed
the project in its early stages questioned whether radio acoustic work would
be successful on the northwest Pacific Coast of the United States on account
of heavy surf noise interfering with the signals and the difficulties of
installing shore stations and cables, while it was taken for granted that
no difficulty would be encountered on the Atlantic Coast. The exact opposite
proved the case and it is only recently in the course of the Georges Bank
work that use under Atlantic Coast conditions has proven practicable.” In “Beginnings
of Acoustic Work in the Coast and Geodetic Survey” by N.H. Heck, in “Association
of Field Engineers U. S. Coast & Geodetic Survey Bulletin,” June
1932, No. 5, p. 48.

1939 - Progress in Mapping the Seafloor

"Surveys of water areas, usually called hydrographic surveys, have
one large handicap not encountered in land surveying -- namely, the sea,
lake, or river bed is usually invisible to the surveyor. This is, perhaps,
the main reason why hydrographic surveys are so fascinating. In addition
to the interesting problems connected with routine tasks - seamanship, handling
of observations, and computations - there is always the anticipation of
finding some new and unsuspected feature of the sea bottom. In conducting
echo sounding surveys there is the additional attraction of being able to
observe the continuous variations in ocean bed topography as the surveying
vessel steams along on the sea surface sometimes a thousand fathoms or more
above the land being mapped. “To a casual observer on a modern surveying
ship that is obtaining echo soundings, and is being controlled in position
by radio-acoustic ranging, the whole process might appear remarkably simple.
But to the engineers, both hydrographic and electrical, and the crews who
have contributed to the development and perfection of some of these methods
and applied them to the surveyors’ needs, it still seems almost incredible
that a system has been devised that is so practical as it is, a procedure
that permits the rapid accumulation of thousands of accurate soundings and
accurate positions of soundings in darkness, fog, or out of sight of visual
control. We look back on this development sometimes and wonder that it has
been made to work so well and realize that many of the most serious difficulties
have not been those of physics and engineering, but those involving skill
and experience in seamanship, and the knowledge and ability that come only
after long experience in dealing with the ever uncertain quantities -- weather
and waves. To the men of the crews, therefore, of the vessels of the Survey
must be given a large share of the credit for success in the “sea
going” use of methods and instruments usually not found outside a
physics laboratory.” In "Atlantic Submarine Valleys of the United
States and the Congo Submarine Valley” by (1939) A.C. Veatch and P.
A. Smith. Published by Geological Society of America (Special Papers Number
7). pp. 53-54.

1939 - Methods, Errors, and Accuracy

"... It is of the utmost importance in any study of these data to
have a thorough knowledge of the methods used, what probable errors to expect,
and the changing relative accuracy as certain improvements increase the
accuracy of the results from year to year; that is to say, one must acquire
at least a speaking acquaintance with many technical details that are second
nature to an experienced hydrographer.” In "Atlantic Submarine
Valleys of the United States and the Congo Submarine Valley” by (1939)
A.C. Veatch and P. A. Smith. Published by Geological Society of America
(Special Papers Number 7). p. 55.

1939 - The Role of Echo Sounding in Exploring the Sea

"Echo sounding has, indeed, opened an almost unlimited field in geology
and related earth sciences. Through it we shall be able to achieve extensive
and intensive exploration of the vast submerged areas of our planet that
hold so much of geologic history hidden under thousands of fathoms of sea.” In "Atlantic
Submarine Valleys of the United States and the Congo Submarine Valley” by
(1939) A.C. Veatch and P. A. Smith. Published by Geological Society of America
(Special Papers Number 7). p. 61.

1939 - New Systems - New Needs

"And thus we advance; what is adequate today may be inadequate tomorrow,
and, as better methods and equipment are perfected and demands for new facts
and knowledge are made, resurveys are periodically necessary. Surveys of
tomorrow doubtless will make those of today seem quite inadequate.” In "Atlantic
Submarine Valleys of the United States and the Congo Submarine Valley” by
(1939) A.C. Veatch and P. A. Smith. Published by Geological Society of America
(Special Papers Number 7). p. 69.

1955 - The Pioneer Survey II

"The Survey had developed a very effective radio navigation system
which could be installed along the coast to provide precise (within a hundred
feet) position information out to distances of a few hundred miles. Existence
of this system is basically what made the entire resulting operation, both
topographic and magnetic mapping, possible.” This quote refers to
the Pioneer survey which was funded by the Navy for determining offshore
bathymetry on the west coast. The Scripps Institution of Oceanography funded
using the first shipboard towed magnetometer from the Pioneer. This convergence
of interests led to the discovery of magnetic striping on the sea floor,
a key element in formulating the theory of Plate Tectonics. In “Some
Origins and Perspectives in Deep-ocean Instrumentation Development” (1980)
by F. N. Spiess. Published in Oceanography the Past (1980) edited by M.
Sears and D. Merriman. Published by Springer-Verlag, New York. p. 230.

1969 - The Need for Accurate Navigation

"One of the problems that has plagued oceanography from its beginning
is the difficulty of establishing position above, on, and beneath the ocean
surface. The requirements for position accuracy differ from place to place
and from problem to problem. In the case of geophysical measurements on
the continental shelf, a precision of a few feet may be required, whereas
for certain biological measurements in the open ocean, an uncertainty of
several miles is acceptable. There are also studies, such as the measurement
of surface currents, where high relative precision, where the order of tens
of yards, is required, but where accurate knowledge of the absolute position
is unnecessary. Certain geophysical studies, such as gravity measurements,
also require precise navigation in order to determine the Eotvos correction....” In
An Ocean Quest - The International Decade of Ocean Exploration (1969) National
Academy of Sciences. p. 92.

1969 - A Global Satellite Navigation System

".... An ideal [navigation] system would include the following characteristics:
global coverage, common geodetic datum, constant availability, unambiguity,
absolute accuracy of at least 200 m, capability of random access, self-monitoring,
relative simplicity at the sensor, capability of providing different ranges
of accuracy, and availability to infinite numbers of users. “....It
would be a synchronous satellite -based system. With ground-tracking stations
located on a common geodetic datum, the spatial positioning of the satellite
could be well determined and monitored. The system should be global ....” In
An Ocean Quest - The International Decade of Ocean Exploration (1969) National
Academy of Sciences. p. 93.

1980 - Wisdom in Using What Works

"... when the opportunity arises one should take whatever proven techniques
he has and go to sea. Waiting for the ultimate system to be available can
lead to indefinite delays and no new science – the better system can
always be used on the next expedition.” In “Some Origins and
Perspectives in Deep-ocean Instrumentation Development” (1980) by
F. N. Spiess. Published in Oceanography the Past (1980) edited by M. Sears
and D. Merriman. Published by Springer-Verlag, New York. p. 230.